Georges St-Pierre says he could return before the end of the year. Anderson Silva was just cleared by USADA and can fight in the fall.

Could the two all-time greats be on a collision course in a fight a decade in the making?

Probably not, GSP told Submission Radio in an interview this week in Australia. The former UFC welterweight and middleweight champion, who is doing a speaking tour of continent, said that he doesn’t think he’d benefit much from fighting Silva at this juncture.

“Right now, I don’t think it’s a win-win situation for me, because I have a lot more to lose than to win right now fighting against Anderson Silva,” GSP said.

Years ago, it seemed like the two would clash in a superfight. GSP was the longtime welterweight champion, holding the title for five years from 2008 to 2013. Silva held the middleweight title from 2006 to 2013. There were talks of the two meeting for a long time and fans clamored for it.

Things are certainly different now. GSP, 37, has not fought since UFC 217 last November, when he returned from a four-year layoff to defeat Michael Bisping and win the middleweight title. Silva has been a bit more active than St-Pierre, but has been out for more than a year dealing with a USADA suspension.

St-Pierre said when they were both champions and the UFC wanted them to fight, he had requested extra drug testing. Silva never tested positive for anything then, but has now popped twice in the last three years. The latter, though, came from a contaminated supplement and USADA gave him a reduced suspension.

The UFC didn’t agree to extra testing at that time, GSP said, though now it uses USADA as its anti-doping partner.

“This fight was interesting at a certain point when I had a lot of contenders in my division,” St-Pierre said. “This fight, if it would have been made, I wanted it to be made with extra performance-enhancing drug testing, which UFC was not a fan about it, because they didn’t want VADA to be a part of it.”

St-Pierre said he also wanted the fight to be a catchweight, because it would be difficult for him to bounce back to welterweight after fighting at middleweight against Silva. The move to middleweight proved a difficult one for GSP last year. Despite beating Bisping, he came down with ulcerative colitis, a digestive issue, after the bout, due to the packing on of pounds.

In an interview with MMA Fighting’s Guilherme Cruz last month, Silva expressed interest in a fight with St-Pierre one day happening.

“Anything is possible in the UFC, man,” Silva said. “It’s a very eclectic company, with a broad vision of the sport. They are going through a new moment, a moment of entertainment, so anything can happen.”